Sol–Gel Route to Nanocrystalline Lithium Metasilicate Particles.

Crystalline lithium metasilicate (Li2SiO3) nanoparticles have been synthesized using a sol–gel process with tetraethylorthosilicate and lithium ethoxide as precursors. The particle size examined by using transmission electron microscopy and BET-specific surface area techniques is in the range 5–50 nm, depending on the temperature at which the material is calcined. The crystalline Li2SiO3 forms at ambient temperature (∼40°C), and it remains in this phase after calcination at temperatures up to 850°C. The BET-specific surface area is ∼110 m2/g for material calcined at temperatures below 500°C, decreasing to ∼29 and ∼0.7 m2/g following calcination at 700° and 850°C, respectively. Solid-state 29Si NMR spectroscopy shows the presence of only Q2 structural units in the material. The lithium metasilicate is further characterized using differential scanning calorimetry and thermogravimetric analysis, and Fourier transform infrared spectroscopy. [ABSTRACT FROM AUTHOR]